/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/PartyBeaconHost.h
Register user auth ticket with the reservation system Must have an existing reservation entry
void RegisterAuthTicket ( const [FUniqueNetIdRepl](API\Runtime\Engine\GameFramework\FUniqueNetIdRepl) & InPartyMemberId, const [FString](API\Runtime\Core\Containers\FString) & InAuthTicket )